The present invention is directed generally to the scrolling of a document on a display screen or the like, and more particularly to various apparatuses and methods for controlling document scrolling using a touch-sensitive scrolling device.
Scrolling of documents, such as word processing documents or Internet web pages, for example, is a common task when using computing systems. There have been recent efforts focusing on methods and techniques for providing pleasant and efficient user interfaces for scrolling. It has been observed that people perform many real-world tasks using both hands. When users operate computers, however, they are often required to use a single hand for many major interface activities, such as moving a mouse. The single hand used is usually the dominant hand of the user. Even when using the mouse to scroll through a document, the dominant hand is typically used. This can be inefficient where the dominant hand may be required for other tasks as well, such as entering numbers on a numeric pad or selecting objects on the screen.
Known methods of scrolling documents are also not as intuitive or easy to use as they could be. For instance, conventional systems typically require that the user first move a cursor on the screen to a scroll bar before scrolling with a mouse, or that the user press arrow keys on a keyboard or rotate a scroll wheel on a mouse. However, some of these techniques do not allow for precise scrolling or the ability to move to a distant portion of the document quickly and accurately. There is a need for better ways to accurately control document scrolling. There is also a need for providing the ability to accurately control document scrolling without the user having to move his or her hands from the keyboard.
According to one aspect of the present invention, a touch-sensitive scrolling device, preferably in the form of an elongated touch-sensitive strip-shaped surface, may be used to manually control scrolling. The scrolling device may, however, be of various shapes, such as square, rectangular, oblong, circular, cross-shaped, X-shaped, and oval.
Various manual scrolling functions may be implemented using the scrolling device. According to an aspect of the present invention, speed-sensitive acceleration of scrolling may be implemented according to an improved acceleration algorithm that allows for precise, slow scrolling at low finger movement speeds and long-distance faster scrolling responsive to rapid movements of the finger (or other pointer) across longer distances.
According to another aspect of the invention, the scrolling device may be placed in absolute scrolling mode such that there is a direct correlation between pointer position on the scrolling device and the scrolled-to location within a document.
According to another aspect of the invention, the scrolling of a document may be rounded, such as to the nearest whole text line. To allow for more accurate scrolling to the nearest whole text line (or other type of rounding), both the actual scroll position and a virtual scroll position may be tracked.
According to yet another aspect of the present invention, unintended scrolling occurring while the user""s finger (or other pointer) is removed from the scrolling device (or in other circumstances) may be reduced or prevented by detecting whether the user""s finger is moving on the scrolling strip so that very small finger motions can be ignored.
These and other features of the invention will be apparent upon consideration of the following detailed description of exemplary embodiments. Although the invention has been defined using the appended claims, these claims are exemplary in that the invention is intended to include the elements and steps described herein in any combination or subcombination. Accordingly, there are any number of alternative combinations for defining the invention, which incorporate one or more elements from the specification, including the description, claims, and drawings, in various combinations or subcombinations. It will be apparent to those skilled in the relevant technology, in light of the present specification, that alternate combinations of aspects of the invention, either alone or in combination with one or more elements or steps defined herein, may be utilized as modifications or alterations of the invention or as part of the invention. It is intended that the written description of the invention contained herein covers all such modifications and alterations.